diff --git a/lib/spack/spack/cmd/patch.py b/lib/spack/spack/cmd/patch.py
index 44fc8696db3..b04b4027384 100644
--- a/lib/spack/spack/cmd/patch.py
+++ b/lib/spack/spack/cmd/patch.py
@@ -24,6 +24,7 @@
 ##############################################################################
 import argparse
 
+import llnl.util.tty as tty
 import spack.cmd
 import spack